Multiple pole, double throw switch



May 29, 1962 J. N. COLE MULTIPLE POLE, DOUBLE THROW SWITCH Filed Nov. 7, 1957 FIGZ.

SIGNAL SOURCE FIGJ.

INVENTOR JAM ES NORMAN COLE HIS ATTORNEYS United States Patent 7 3,037,125 MULTIPLE POLE, DOUBLE THROW SWITCH James Norman Cole, Peekskill, N.Y., assignor to International Business Machines Corporation, New York, N.Y., a corporation of New York Filed Nov. 7, 1957, Ser. No. 695,076 Claims. (Cl. 307-88) This invention relates to magnetic cores and, more particularly, to a switching device utilizing magnetic cores.

Magnetic cores wherein the magnetic flux path may assume any of a number of configurations in response to external influences and wherein the flux remains in the condition last induced exhibit magnetic remanence and may be utilized as memory or storage devices. In addition, by inducing certain magnetic flux conditions linking a pair of coil windings, the transmission of information from one winding to the other may be controlled.

Frequently, it is desired to transmit information to either of two groups of receptors but not to the other, and to switch to the other group while discontinuing transmission to the first. Conventional mechanical multiple pole double throw switches designed to accomplish this are not only inconveniently large for certain installations, but also are relatively slow in operation, require substantial electrical energy, and eventually wear out and must be replaced.

Accordingly, it is an object of the present invention to provide a new and improved multiple pole double throw switch utilizing magnetic cores.

Another object of the present invention is to provide a high speed switch of the above character wherein no mechanical operation is involved.

A further object of the invention is to provide an electrically operated multiple pole double throw switch capable of low power operation.

These and other objects of the invention are attained by arranging each of a pair of magnetic cores with control means adapted to create desired changes in the magnetic flux paths within the cores. Each of the cores has information input and output windings which may be inductively linked to transmit information when the flux paths are arranged in one condition to complete magnetic circuits between them. In another condition, the flux paths induced in the cores pass through the input and output windings in opposed directions, thus preventing the transmission of information. Double throw switching operation is obtained by maintaining opposite flux conditions in the two cores and reversing the conditions when desired.

Further objects and advantages of the invention will be apparent from the reading or" the following description in conjunction with the accompanying drawings in which:

FIG. 1 is a schematic diagram illustrating the circuit of a typical multiple pole double throw switch arranged according to the invention; and

FIGS. 2 to 4 illustrate various flux paths in the magnetic cores shown in FIG. 1.

As illustrated in FIG. 1, the switch circuit comprises a pair of apertured magnetic cores and 10" which may be identical, each having a control aperture 111, 11 piercing one section of the core and two or more adjacent output holes 12, 12a, 12, 12a passing through another section of the core. Inasmuch as each of the holes 11, 11', 12, 12a, 12, and 12a is positioned in the path of the magnetic circuit, two passages for magnetic flux are created on opposite sides of each hole.

In order to induce opposite magnetic states in the two cores 10 and 10, a conductor 13 leads from a first switch terminal 14 to ground through a coil winding 15 wound around one passage of the core 10 adjacent the 3,037,125 Patented May 29, 1962 ice control hole Ill and also through another winding 16 which passes completely around a section of the core 10. Reversal of the core states is accomplished through a similar conductor 13 leading from a second switch terminal 14' to a winding 15 embracing one passage adjacent the hole 11' and on to ground through another winding 16' entirely surrounding a section of the core 10, the windings 15 and -15 being arranged to oppose the flux induced by the coils 16 and 16, respectively.

Information in the form of alternating current signals or sequential pulses of opposite polarity from an A.C. signal source 17, for example, is carried through input coils 18 and 18' wound around passages of the cores 10 and 10' through the holes 12 and I12 respectively, by a conductor 19. It will be understood that signals from different sources may be applied to the windings 18 and '18, if desired, and that difierent signals to be controlled in the same manner may be induced in other windings 18a and 18a passing through the other holes 12a or 12a. Embracing the passages created by the holes 12 and 12', output windings 20 and 20' lead to pairs of terminals 21 and 21' respectively at which signals transmitted by the switch may be detected. Similarly, signals transmitted from the windings 18a and 18a appear at the corresponding windings 20a and 20a.

In operation, a direct current pulse applied to the switch terminal 14 passes through the winding 15 inducing a magnetic field in one passage of the core 10, and also in the section of the core embraced by the coil 16, the latter coil being of sufficient strength to influence the magnetic flux throughout the core and being wound so as to generate a continuous flux path around the core 10', as shown by the dotted lines in FIG. 1. Meanwhile, the winding 15, having less magnetic strength and enclosing only a passage of the core 10 creates a circular flux path around the hole 11 opposing any continuous path, thus turning back, or kidneying, the magnetic paths in its vicinity.

Referring to FIG. 2, it will be observed that the flux paths created in the vicinity of the holes 12 and 12a as a result of this kidneying pass in one direction on one side of any hole and in the opposite direction on the other side. On the other hand, the flux paths of the continuous circuit adjacent the holes 12 and 12a in FIG. 1 pass in the same direction, thus opposing any magnetic circuit around these holes and preventing inductive linkage between the input coils 18' and 18a and the output coils 20' and 20a for input signals below a certain magnitude. However, A.C. signals from the conductor 19 of insufiicient strength to be transmitted to the output coil 20' are capable of completing a magnetic loop around the hole 12 in the kidneyed core 10 to induce signals in the output winding 20 in the manner illustrated in FIG. 3. Therefore, the magnetic path condition shown in the core 10' in FIG. 1 is the off condition and that shown in FIGS. 2. to 4 is the on condition. In a similar manner, signals applied to input coils 18a embracing other adjacent holes 12a will be transmitted to corresponding output windings 20a through magnetic loops surrounding those holes as shown in FIG. 4, thus carrying out the multiple pole function of the switch.

When a direct current pulse is applied to the terminal 14', the role of the two cores 10 and 10' is reversed by the action of the windings 15 and 16, the core 10 being switched to the off condition and the core 10 to the on condition as described above. In this manner, the switch completes a double throw operation and signals carried by the line 19 now appear at terminals 21 but not at the terminals 21.

It will be noted that, inasmuch as the input coils 18, 18a and output windings 20, 20a are linked to opposite passages adjacent each hole 12, a magnetic circuit around the hole must be completed in the manner described in order to permit transmission of signals from the input to the output windings. Thus, the tendency to induce signals in the output windings when the core is off, which occurs in switches wherein the input and output windings embrace the same passage and the off condition is dependent upon the saturation of residual flux to oppose the flux induced by input signals, is substantially eliminated. Further, it will be observed that inasmuch direct current pulse signals applied to the input coils 13, 18', will not necessarily complete a flux path around the hole 12, depending on their direction, the invention is peculiarly adapted to the control of information represented by sequential pulses of opposite polarity or by AC. signals and tends to prevent spurious output indications resulting from random variations in the D.C. input potential.

Although the invention has been described herein with reference to a specific embodiment, many modifications and variations therein will occur to those skilled in the art. Accordingly, the invention is not intended to be restricted in scope except as defined by the following claims.

I claim:

1. A double throw magnetic switch comprising first and second magnetic cores each forming a closed magnetic flux circuit and capable of assuming bistable states of remanence, said cores each having a plurality of output apertures, each output aperture dividing the magnetic flux circuit into two passages, input coil means for each output aperture inductively linked to the magnetic flux in one passage only, output coil means for each output aperture inductively linked to the magnetic flux in the other passage only, first magnetic flux control means adapted to permit the completion of magnetic circuits linking the two passages for-med by each of the output apertures in the first core and simultaneously to oppose the completion of magnetic circuits linking the two passages formed by each of the output apertures in the second core, and second magnetic flux control means adapted to permit the completion of magnetic circuits linking the two passages formed by each of the output apertures in the second core and simultaneously to oppose the completion of magnetic circuits linking the two passages formed by each of the output apertures in the first core.

2. A magnetic switch according to claim 1 wherein the first magnetic flux control means comprises first coil means completely enclosing a portion of the magnetic circuit in the second core, a control aperture dividing the magnetic flux circuit in the first core into two passages, and second coil means inductively linked to the magnetic flux in one of these passages, and the second magnetic flux control means comprises first coil means completely enclosing a portion of the magnetic circuit in the first core, a control aperture dividing the magnetic flux circuit in the second core into two passages, and second coil means inductively linked to the magnetic flux in one of these passages.

3. A double throw magnetic switch comprising first and second magnetic cores each forming a closed magnetic flux circuit and capable of assuming bistable states of remanence, said cores each. having a plurality of output apertures, each output aperture dividing the magnetic flux circuit into two passages, input coil means for each output aperture inductively linked to the magnetic flux in one passage only, output coil means for each output aperture inductively linked to the magnetic flux in the other passage only, first magnetic flux control means for each core adapted to induce a continuous magnetic circuit throughout the core, second magnetic flux control means for each core adapted to kidney the magnetic flux in the core, circuit means connecting the first control means for the first core and the second control means for the second core for simultaneous actuation and circuit means connecting the second control means for the first core and the first control means for the second core for simultaneous actuation.

4. A magnetic switch according to claim 3 wherein the first magnetic flux control means for each core comprises coil means completely enclosing a portion of the magnetic circuit in the core.

5. A magnetic switch according to claim 3 wherein the second magnetic flux control means for each core comprises a control aperture dividing the magnetic circuit in the core into two passages and coil means inductively linked to one of the passages.

References Cited in the file of this patent UNITED STATES PATENTS 2,802,953 Arsenault et a1 Aug. 13, 1957 2,803,812 Rajchrnan Aug. 20, 1957 2,896,194 Crane July 21, 1959 2,921,136 Cooke Ian. 12, 1960 OTHER REFERENCES The Transfiuxor from Proceedings of The IRE, March 1956, pages 321-332. 

